The present invention relates to an image forming apparatus and, more particularly, to an improvement in the developer replenishment mechanism of the image forming apparatus.
An image forming apparatus for forming an electrostatic latent image on an image carrier, developing the image with toner in a developing unit, and transferring the toner image onto a sheet, comprises a container (toner cartridge or toner bottle) for replenishing the developing unit with toner. This toner cartridge has a spiral on its inner surface. When the toner cartridge itself rotates, the contained toner is squeezed out from an outlet port along the spiral and supplied to the developing unit.
The outlet port of the toner cartridge is open in mounting a new toner cartridge on the apparatus main body or dismounting an empty toner cartridge from the apparatus main body. For this reason, toner escapes from the outlet port and scatters in the apparatus to contaminate the apparatus.